Lifting device



April 14, 1942. A K 2,279,465

' LIFTING DEVICE Filed Oct. 30, 1940 Fiai 1*) Fica2 a Mo ALEX/6 inc/rso/v INVENTOR.

ATTORNEY Patented Apr. 14, 1942 a it 'i FFECE LIFTING DEVICE ApplicationOctober 30, 1940, Serial No. 363,399

Claims.

My invention relates to lifting devices and has particular reference todevices for lifting various objects such as automotive vehicles.

In my United States patent application Serial No. 309,324, filedDecember 15, 1939, patented February 4., 1941, as Patent 2,239,250, Idisclosed a lifting jack employing a base mounting pivoted arms, thefront ends of the arms being adapted to raise an object such as anautomobile axle. The arms are supported on links pivoted at the rearends to posts on the frame and pivotally connected to blocks slidablymounted on intermediate portions of the arms, A motor is mounted on thearms for moving the sliding blocks, thereby raising the arms.

I have found that for certain purposes it is de sirable to mount themotor directly on the frame or on the rear posts in order to leave thearms free. The sliding blocks can be then moved closer to the rear end,increasing the total movement of the blocks and, therefore, increasingthe lift Without lengthening the arms.

In one modification of this device the motor is pivotally mounted on theposts. Although any suitable type of a motor can be used such aselectric or hydraulic, I prefer to use an air motor consisting of acylinder and piston with a piston rod connected to the sliding block. Thcylinder is pivotally mounted on the posts, preferably at its front endso as to make it self-aligning with the piston rod, i. e., with thedirection of the force produced by the compressed air in the cylinder.

In another modification of my device, the cylinder is also pivoted tothe posts or to the frame, the piston rod being pivotally connected tothe intermediate portion of the links, thereby increasing the travel ofthe sliding block for a relatively short movement of the piston.

In another modification the links are pivotally connected to theintermediate portion of the lifting member, the rear ends of the linksbeing pivotally connected to a block sliding vertically on the upperends of the posts. The cylinder is mounted on the base, preferablyrigidly, the piston rod being connected to the sliding block. In thelatter arrangement the piston rod may be also pivoted to theintermediate portions of the links, the cylinder being also pivoted tothe frame or to the posts.

My invention is more fully described in the accompanying specificationand drawing, in which:

Fig. 1 is an elevational view of my lifting device partly in section;

Fig. 2 is an end View of the same;

Fig. 3 is a top plan view of the same;

Fig. 4 is a detail view 'of a sliding block on a lifting arm of mydevice;

Fig. 5 is an elevational view of a modified device;

Fig. 6 is an end View of the same;

Fig. 7 is an elevational view of another modification; and

Fig. 8 is an end view of the same.

My lifting device consists of a frame forming a base of my device. Itmay consist of two side beams 5i joined at the ends by cross bars 52 and53 and mounted on wheels 54 rotating on shafts 55 and 55. The shaft 55also supports the rear end of a lifting member 51, the front end of thelatter being provided with a hook 58 adapted to engage and to supportanobject to be lifted, such as an axle of an automotive vehicle.

The frame beams 5| have raised portions or posts 59 at the rearconnected at the top by a shaft Bil which supports the upper ends oflinks Bl The lower or front ends of the links are pivoted at 62 to thesides of a block 63 slidably engaging the upper side of the arm orlifting member 51, which is preferably made in the form of an I-beam.The lifting member 51 can be raised to a position indicated .in dottedlines in Fig. 1 by moving the sliding block 63 forward. This movementcan be accomplished by any suitable motor mounted on the raised portions9 of the frame, but I prefer to use an air motor in the form of acylinder 64 closed at the rear and open at the front and having a piston65 sliding inside, the piston being provided with a rod 66 rigidlyconnected thereto and pivoted on the shaft 62 of the block 63. Thecylinder has ears or front extensions 61 supporting trunnions 68rotatively fitted in the posts 59. Compressed air or other fluid underpressure is delivered to the cylinder by a flexible tube 69 providedwith a suitable one-way valve (not shown), if desired.

Due to the location of the pivoting trunnions 68 between the piston 65and the shaft 62, the cylinder is made self-centering, i. e., it alwaysaligns itself with the piston rod, rotating on its trunnions between thetwo extreme positions indicated in solid and dotted lines respectivelyin Fig. 1. The self-aligning feature is further enhanced by mounting thecylinder on extensions or ears 6?, thereby moving the piston fartherback of the trunnions.

In a modified construction shown in Figs. 5 and 6, the piston rod 66 ispivoted to the intermediate portions of the links 6! at 1.0, so that arelatively short cylinder can be used for the same movement of thelifting member 51.

In another modification shown in Figs. '7 and 8, the links 6| arepermanently pivoted to the intermediate portion of the lifting member51', the rear ends of the links 6| being pivotally connected to a shaftH whose ends slide in slots 12 provided in the upper portions of rearposts or frame extensions 13, connected at the top by a cross bar M.

The lifting member is raised by moving the shaft H upward in the slots12. This movement can be conveniently accomplished by an air motorconsisting of a cylinder 15 rigidly mounted on the frame between theposts 13. A piston 65 slides in the cylinder and is provided with a rod65 pivoted to the middle portion of the shaft H.

It should be noted that the links El can be connected into a single linkmember, i. e., they can be integrally joined together into a singleelement. Similarly the two posts 59 or 13 can be integrally joinedtogether into a single member.

It is understood that my lifting device may be further modified withoutdeparting from the spirit of this invention, as set forth in theappended claims.

I claim as my invention:

1. A lifting device comprising a frame forming a base having a raisedrear portion, a lifting member having its rear end pivotally supportedat the rear portion of the frame, the front end of the lifting memberbeing adapted to raise a load, a link member extending in tensionbetween the raised portion of the frame and lifting member, one end ofthe link member being pivoted and the other end having a slidingconnection, and a motor interposed between the frame and theintermediate portion of the link member for moving the slidingconnection, thereby raising the lifting member.

.2. A lifting device comprising a frame forming a base having a raisedrear portion, a lifting member having its .rear end pivotally supportedat the rear portion of the frame, the front end of the lifting memberbeing adapted .to raise a load, a link member extending between theraised portion of the frame and lifting member, one end of the linkmember being pivoted to th raised portion of the frame and the other endhaving a sliding connection with the lifting member, and means on theframe for moving the sliding connection, thereby raising the liftingmember,

3. A lifting device comprising a frame forming a base having a raisedrear portion, a lift- 1 ing member having its rear end pivotallysupported at the rear portion of the frame, the front end of the liftingmember being adapted to raise a load, a link member extending in tensionbetween the raised portion of the frame and lifting member, one end ofthe link memher being pivoted and the other end having a slidingconnection, and a motor pivotally supported on the frame engaging theintermediate portion of th link member for moving the slidto raise aload, .a link member extending between the raised portion of the frameand lifting member, one end of the link member being pivoted to theraised portion of the frame and the other end having a slidingconnection with the lifting member, a cylinder having an open and aclosed end pivotally connected to the raised portion of the frame at itsopen end and extending rearward of the frame, a piston in the cylinder,and extending from the piston pivotally connected to the slidingconnection, and means to admit a fluid under pressure into the cylinder,thereby raising the lifting member.

5. A lifting device comprising a frame forming a base having a raisedrear portion, a lifting member having its rear end pivotally supportedat the rear portion of the frame, the front end of the lifting memberbeing adapted to raise a load, a link member extending between theraised portion of the frame and lifting member, one end of the linkmember being pivoted to the raised portion of the frame and the otherend having a sliding connection with the lifting member, and means onthe frame for raising the link member, thereby raising the liftingmember.

6. A lifting device comprising a frame forming a base having a raisedrear portion, a lifting member having its rear end pivotally supportedat the rear portion of the frame, the front end of the lifting memberbeing adapted to raise a load, a link member extending between theraised portion of the frame and lifting member, one end of the linkmember being pivoted to the raised portion of the frame and the otherend having a sliding connection with the lifting member, a cylinderhaving an open and a closed end mounted on the frame, a piston slidablyfitted in the cylinder, a rod extending from the piston pivotallyconnected to the intermediate portion of the link member, and means toadmit a fluid under pressure into the cylinder for raising the liftingmember.

'7. A' lifting device comprising a frame forming a base having a raisedrear portion, a lifting member having its rear end pivotally supportedat the rear portion of the frame, the front end of the lifting memberbeing adapted to raise a load, a link member extending between theraised portion of the frame and lifting member, one end of the linkmember being pivoted to the raised portion of the frame and the otherend having a sliding connection with the lifting member, and a motor onthe frame operatively connected with the sliding end of the link formoving the sliding connection, thereby raising the lifting member.

8. A lifting device comprising a frame, posts at the rear of the frame,a lifting member pivotally connected to the rear portion of the frame,the front end of the lifting member being adapted to raise a load, ablock slidably sup- ..ported on the lifting member, links pivotallyconnected to the block and to the upper ends of the posts, a motor onthe frame, and means to move the block by the motor, thereby raising thelifting arms.

9. A lifting device comprising a frame, posts at the rear of the frame,a lifting member pivotally connected to the rear portion of the frame,

the piston pivotally connected with the block, and means to admit afluid under pressure into the cylinder for raising the lifting member.

- 10. A lifting device comprising a base, an arm member pivotallysupported on said base and adapted to support a load at its movable end,a post member rigidly mounted on said base and extending upwardly, saidarm member having a guideway, said post member having a pivot device, acarrier on said guideway, a motor for moving said carrier along saidguideway, and a bar connected at one end to said pivot device and at theother end to said carrier, whereby raising said carrier causes themovable end of said arm member to b raised.

ALEXIS JACKSON.

